Resistance-adjusting device



June 23, 1925.

E. E. YAXLEY RESISTANCE ADJUSTING DEVICE M m E ,06 i E 0 /wHUWUU/Vvv Filed May 26. 1924 Patented June 23, 1925.

UNITED STATES PATENT OFFICE.

Application led lay 26, 1924. Serial No. 716,009.

To all whom z't may concern.'

Be it known that I, ERNEST E. YAxLEY, a citizen of the United States, residing at Chicago, in the county of Cook and the State I of Illinois, have invented a certain new and useful Improvement in Resistance-Adjusting Devices, of which the following is a full, clear, concise, and exact description.

My invention relates to resistance adjustl 'ing devices such as ordinary rheostats and rheostats entering into the construction of variometers.

The resistance adjusting device of my invention includes a band, preferably of insulation, resistance wire coiled about the band, a disk or support upon which said band and resistance wire are carried and-a switch arm having a contacting end 1n .changeable engagement with saidV wire, the

arm and support being relatively rotatable.

In accordance with one feature of the invention, the periphery of the disc has a depression receiving one end of the band and there is an assembling block carried by the disc and engaging this end of the band to hold it in said depression. The other end of the band desirably has a lateral extension, and the' disc has a flange portion formed with a recess upon its inner side that receives said extension to anchor the end of the band having the extension. In accordance with another feature of the invention, as embodied in a rheostat, one end of the band, preferably the end last mentioned, extends beyond the coiled resistance wire and there is an element, referably of metal, overlying this end of tlie band, the contacting end of the arm being engageable, at one time, with said metal element and the ad'awith said metal element alone, to avoid jarring of the contact as it rides out of connection with the wire. This metal element is preferably in the form of a strip having a ump near the resistance Wire and beyond which said contact is adapted to be positioned to hold the arm out of engagement with the adjacent end of the wire.

The invention will be more fully explained in connection with the accompanymgdrawing in which Fig. 1 is a face view of the preferred form of resistance adjusting device, parts being broken away; Fig. 2 is a sectional view on line 2 2 of Fig. 1;

cent end of the coiled resistance wire and a so Fig. 3 is a plan view on a larger scale of a part of the structure shown in Figs. 1 and 2 with the switch arm and other parts removed; Fig. 4 is a sectional view, on line 4 4 of Fig. 1; and Fig. 5 is a perspective view illustrating the assembly of the ends of the wire supporting band with the disk. The structure illustrated includes a stationary hub portion 1,- having a reduced threaded end receiving a nut 2 whereby said hub portion may be clamped upon a mounting panel 3. A disc of insulation 4 is carried by the hub 1. This disc is sandwiched between two thinner discs 5 and 6, also made of insulation, all of the discs being co-axial to define an annular groove, the dlscs 5 and 6 constituting flanges of the disc 4. The three discs are desirably clamped against the inner side of the panel by the nut 2, together with a bracket 6 carrying a coiled conductor connected with the shaft 19. The band of insulation 7 vhas resistance wire 8 coiled about it, the band thus wound with wire being disposed in said annular groove and being supported upon the periphery 6. The disc 4 is formed with an arcuate depression 9 in its periphery, and one end of the band 7 terminates in an arcuate portion 10 which is received in this depression. A

block 11 has a lower arcuate portion 12 which is received in the depression 9 and which serves to hold the band end 10 in assembl assem led with the flange 6 by a riveting pin 13. An element 14, preferably in the form of a metal strip, has an arcuate end 15 which is also held by the block portion 12 in the depression 9. The stri overlies the other end of the band 7 which projects beyond the coiled wire 8, the stri being formed with a hump 15 adjacent and) spaced apart from the wire. The end of the band which underlies the strip 14 is formed with a lateral extension 16 that enters a recess 17 provided upon the inner side of the fiange 6 and preferably extending therethrough. The flange 5 is applied after the lateral extension 16 is placed in the recess 17 and holds the band and its lateral extension in place.

The switch arm 18 is fixed upon the inner end of the shaft 19 which is journaled in the stationary hub 1. This switch arm is provided with a knob 20 secured to the shaft with the disc 4. The block 11 is.

19 by a set screw 21. A contact 22 is provided upon the outer end of the switch arm and extends into the channel between the lan'ges 5 and 6 into engagement with the resistance wire that is bare to have electrical connection with this contact. When all of the resistance is to be excluded, as in an ordinary rheostat, the range of movement of the switch arm is such and the coiled resistance wire is so reduced in length that said contact may ride out of engagement therewith. In order to avoid a jolting or bumping movement when the contact leaves the wire, such contact is made sufficiently long, in a circular direction, as to at one time be engageable with both the wire and the strip 14, this strip being spaced apart :trom the wire in the direction of relative movement of the arm and wire, the strip and the contact being so proportioned that the contact may thereafter have engagement with said strip alone. The contact may ride over the hump l5 so that the contact may not be accidently arred or otherwise moved by very slight force, accidently exerted, into engagement with the wire.

lhanges may be made without departing from my invention.

Having thus described my invention, I claim:

1. A resistance adjusting device including a band of insulation; resistance wire coiled about said band; a support upon which said band and the resistance wire on the band are carried, said band being anchored at its Aends to the support and projecting beyond the coiled wire at one end; an element overlying said projecting end of the band; and a switch arm having a contact bearing upon said resistance wire, said arm and support being relatively rotatable, said Contact being engageable, at one time, with said element and the adjacent end of the coiled resistance wire and also with said element alone, said element being spaced apart from the wire in the direction of relative movement of the arm and wire.

2. A resistance adjusting device including a band of insulation; resistance wire coiled about said band; a support upon which said band and the resistance wire on the band are carried, said band being anchored at its ends to the support and projecting beyond the coiled wire at one end; a strip overlying said projecting end of the band; and a switch arm having a Contact bearing upon said resistance wire, said arm and support being relatively rotatable, said contact being engageable, at one time, with said strip and the adjacent end of the coiled resistance wire and also with said strip alone,. said strip being spaced apart from the wire in the direction of relative movement of the arm and wire, this strip having a hump next the resistance wire over and beyond which said contact is adapted to be positioned and which holds this contact apart from the adjacent end of the resistance wire.

3. A resistance adjusting device includinfr a band; resistance wire coiled about said band; a disc upon whose periphery said band and the resistance wire on the band are supported, the periphery of said disc having a depression receiving one end of said band; an assembling block carried by the disc and engaging this end of the band and holding the same in said depression; and a switch arm having a contact in changeable engagement with said wire.

4. A resistance adjusting device including a band; resistance wire coiled about said band; a disc upon whose periphery said band and the resistance wire on the band are supported, the periphery of said disc having a depression receiving one end of said band; an assembling block carried by the disc and engaging this end of the band and holding the same in said depression, the other end of the band having a lateral ex tension, and said disc having a flange portion formed with a recess upon its inner side that receives said extension to anchor the latter end of the band; and a switch arm having a contact in changeable engagement with said wire.

A resistance adjusting device including a band; resistance wire coiled about said band; a disc upon whose periphery said band and the resistance wire on the band are supported, said disc having a flange por tion Yformed with a recess and one end of said band having a lateral extension received in said recess, whereby the disc and band are assembled to move together; and a switch arm having a contact in changeable engagement with said wire.

6. A resistance adjusting device including a band; resistance wire coiled about said band; a disc upon whose periphery said band and the resistance wire on the band are supported, the periphery of said disc having a depression receiving one end of said band; an assembling block carried by the disc and engaging this end of the band and holding the same in said depression, the other end of' the band having a lateral extension, and said disc having a flange portion formed with a recess upon its inner side that receives said extension to anchor the latter end of the band, said disc also having another flange portion on its side opposite the first flange portion and engaging said band to hold its lateral extension in said recess, whereby the disc and band are assembled to move together; and a switch arm having a contact in changeable engagement with said wire.

7 A resistance adjusting device including a. band; resistance wire coiled about said band; a disc upon whose periphery said band and the resistance wire on the band are supported, said disc-having a. ange portion formed with a recess and one end of said band havng a lateral extension received in said recess, said disc also having another Hang@ portion on its side opposite the first flange portion and engaging said band to hold its lateral extension in said recess7 whereby the disc and band are assembled to move together; and a switch 10 arm having a Contact in changeable engagement with said Wire.

In Witness whereof, I hereunto subscribe my name.

ERNEST E. YAXLEY. 

